A printing device includes a feeding portion configured to feed a print medium along a feed direction, a printing portion configured to perform printing on the print medium fed by the feeding portion, the printing being performed for each of a print line extending in a direction orthogonal to the feed direction, a storage portion configured to sequentially store print data received from the external device, and a processor configured to determine whether consecutive identical data are accumulated in the storage portion, the consecutive identical data being identical print data for a predetermined number of the print lines that are consecutive in the feed direction, and cause the printing portion to start the printing based on the print data stored in the storage portion when it is determined that the consecutive identical data are accumulated.